Common-mode signaling for transition encoding

Abstract

A method for transmitting an input stream of data across a serial link including a serial channel. The method includes segmenting the stream of data into blocks of bits to form input blocks, and for each input block, calculating a measure of burst error probability, forming an output block and a modification signaling bit from the input block, transmitting the output block, and transmitting the modification signaling bit. The forming of the output block and the modification signaling bit from the input block includes, when the measure of burst error probability exceeds a set threshold: modifying the input block to form the output block, and asserting the modification signaling bit.

What is claimed is: 
     
       1. A method for transmitting an input stream of data across a serial link comprising a transmitter and a serial channel, the method comprising:
 segmenting the stream of data into blocks of bits to form a plurality of input blocks; 
 for an input block of the plurality of input blocks:
 calculating, by the transmitter, a measure of burst error probability; 
 forming an output block and a modification signaling bit from the input block; 
 transmitting the output block; and 
 transmitting the modification signaling bit, 
 the forming of the output block and the modification signaling bit from the input block comprising:
 when the measure of burst error probability exceeds a set threshold:
 modifying the input block to form the output block; and 
 asserting the modification signaling bit, and 
 
 when the measure of burst error probability does not exceed the set threshold:
 forming the output block to be equal to the input block; and 
 de-asserting the modification signaling bit, 
 
 
 
 wherein the calculating of a measure of burst error probability comprises counting consecutive transitions in the input block. 
 
     
     
       2. The method of  claim 1 , wherein the threshold is equal to m/2−1 wherein m is the length of the input block. 
     
     
       3. The method of  claim 1 , further comprising transmitting the output block on the serial channel and transmitting the modification signaling bit on the serial channel. 
     
     
       4. The method of  claim 3 , wherein the transmitting of the output block on the serial channel comprises transmitting the output block on the serial channel utilizing differential signaling. 
     
     
       5. The method of  claim 3 , wherein the transmitting of the modification signaling bit on the serial channel comprises transmitting the modification signaling bit on the serial channel utilizing common-mode signaling. 
     
     
       6. The method  claim 1 , further comprising:
 receiving a block; 
 receiving a modification signaling bit; and 
 applying an inverse modification to the block when the modification signaling bit is asserted. 
 
     
     
       7. The method of  claim 6 , further comprising transmitting the output block on the serial channel and transmitting the modification signaling bit on the serial channel. 
     
     
       8. The method of  claim 7 , wherein the transmitting of the output block on the serial channel comprises transmitting the output block on the serial channel utilizing differential signaling. 
     
     
       9. The method of  claim 7 , wherein the transmitting of the modification signaling bit on the serial channel comprises transmitting the modification signaling bit on the serial channel utilizing common-mode signaling. 
     
     
       10. The method of  claim 1 , wherein the threshold is equal to m/2−1 wherein m is the length of the input block. 
     
     
       11. A method for transmitting an input stream of data across a serial link comprising a transmitter and a serial channel, the method comprising:
 segmenting the stream of data into blocks of bits to form a plurality of input blocks; 
 for an input block of the plurality of input blocks:
 calculating, by the transmitter, a measure of burst error probability; 
 forming an output block and a modification signaling bit from the input block; 
 transmitting the output block; and 
 transmitting the modification signaling bit, 
 the forming of the output block and the modification signaling bit from the input block comprising:
 when the measure of burst error probability exceeds a set threshold:
 modifying the input block to form the output block; and 
 asserting the modification signaling bit, and 
 
 when the measure of burst error probability does not exceed the set threshold:
 forming the output block to be equal to the input block; and 
 de-asserting the modification signaling bit, 
 
 
 
 the method further comprising:
 receiving a block; 
 receiving a modification signaling bit; and 
 applying an inverse modification to the block when the modification signaling bit is asserted, 
 
 wherein the receiving of the modification signaling bit comprises:
 obtaining a plurality of samples of the modification signaling bit; and 
 performing majority detection on the samples. 
 
 
     
     
       12. The method of  claim 11 , wherein the calculating of a measure of burst error probability comprises counting consecutive transitions in the input block. 
     
     
       13. The method of  claim 12 , wherein the threshold is equal to m/2−1 wherein m is the length of the input block. 
     
     
       14. The method of  claim 11 , further comprising transmitting the output block on the serial channel and transmitting the modification signaling bit on the serial channel. 
     
     
       15. A system for transmitting an input stream of data across a serial link comprising a serial channel, the system comprising a transmitter configured to receive the input stream of data, the transmitter being configured to partition the stream of data into a plurality of input blocks, the transmitter comprising a burst error detector configured to:
 calculate a measure of burst error probability; and 
 identify input blocks of the plurality of input blocks having a measure of burst error probability exceeding a threshold, 
 wherein the burst error detector is configured to identify input blocks of the plurality of input blocks having a measure of burst error probability exceeding a threshold by counting consecutive transitions in the input blocks of the plurality of input blocks. 
 
     
     
       16. The system of  claim 15 , wherein the transmitter is further configured to:
 transmit a plurality of output blocks and a plurality of modification signaling bits, wherein:
 output blocks of the plurality of output blocks corresponding to the identified input blocks are formed by modifying the respective identified input blocks, and 
 modification signaling bits of the plurality of modification signaling bits corresponding to the identified input blocks are asserted. 
 
 
     
     
       17. The system of  claim 16 , further comprising a receiver configured:
 to receive:
 a plurality of received blocks, each corresponding to one of the plurality of transmitted output blocks and 
 a plurality of received modification signaling bits, each corresponding to one of the plurality of transmitted modification signaling bits and 
 
 to perform an inverse modification on each received block associated with a received modification signaling bit that is asserted. 
 
     
     
       18. The system of  claim 17 , wherein the burst error detector is configured to identify input blocks of the plurality of input blocks having a measure of burst error probability exceeding a threshold by counting consecutive transitions in the input blocks of the plurality of input blocks. 
     
     
       19. The system of  claim 18 , wherein the transmitter is configured to modify the identified input blocks by inverting every other bit of each identified input block, and the receiver is configured to perform an inverse modification by inverting every other bit of each received block of the plurality of received blocks on which an inverse modification is to be performed.